This invention relates generally to spacing devices which are used to support reinforcing materials prior to the time that those materials become imbedded within concrete structures; more particularly, the invention relates to a support which is adapted to be affixed to and move with a reinforcement cage as that cage is lowered into a prior hole--just prior to the time that concrete is poured into the hole.
It is well known to reinforce concrete piers (and other concrete structures) with steel reinforcing rods. And, it is also known to provide spacers in order to hold reinforcing rods or mesh away from the sides of concrete forms. Examples of such spacers of the prior art are shown in the following U.S. Pat. Nos. 790,230 to Stempel entitled "Method of Protecting Piles or the Like"; 1,708,277 to Martin entitled "Device for Positioning the Reinforcement of Concrete Structures"; 3,722,164 to Schmidgall entilted "Spring Wire Spacer, Especially for Spacing Reinforcing Mesh from the Form in the Manufacture of Concrete Structures and the Like"; 3,257,767 to Lassy entitlted "Snap-On Spacer Positioner for Reinforcement"; and 3,471,986 to Swenson entitled "Spacer for Reinforcing Mesh for Concrete Pipe and the Like". A characteristic of all of the spacers that have been identified, however, is that they are only operable within smooth, rigid forms. That is, the wire spacers exemplified by Schmidgall, Swenson and Lassy may well be perfectly suited for use in a form for casting concrete pipe or the like; but the relatively sharp "point" that is intended to bear against a rigid mold or form would be total unsuitable for the raw earth that surrounds a pier hole (or drilled shaft) that is about to be poured full of concrete. The act of lowering a reinforcement cage into a typical pier hole with such sharply pointed spacers could cause the points to act like small plows, digging a groove into the soil and/or knocking clods of dirt down into the hole. An alert inspector who noticed that the bottom of the hole was becoming fouled with loose dirt could demand that the entire cage be withdrawn and the hole cleaned before permitting the pouring of concrete. Of course, the step of removing and then replacing such a cage would likely compound the problem by moving the heavy cage along the sides of the pier hole two more times. Hence, there has long remained a need for a spacing device which could provide for piers the spacing advantages that are available for cast concrete pipe and the like, while not introducing a risk of deterioration of the sidewall of the hole; and it is an object of this invention to provide such a spacer.
It is another object to provide a dynamic guide for a reinforcement cage, so that the cage may be used in situations where soil conditions would make installation of an unprotected cage impractical.
Still another object is to provide a spacer for a steel reinforcing rod in order to ensure that it will eventually be imbedded within concrete, such that ground water and/or corrosive soils will not have a chance to come into contact with the rod and contribute to its corrosion and eventual failure.
One more object is to provide a spacer having sufficient strength as to ensure that a reinforcing cage will remain centered in a pier hole, even when fluid concrete is acting to force that cage to a non-centered position. This and other objects will be apparent from a reading of the specification and the claims appended thereto, with appropriate reference to the drawing provided herewith.